Electromagnetic relays



y 4, 1966 w. J. RlCH ERT 3,253,095

ELECTRQMAGNETI C RELAYS Filed Aug. 30, 1963 2 Sheets-Sheet 1 ,34 as \F-29 INVENTOR Walter J. Richert ATTORNEYS May 24, 1966 w. J. RICHERTELECTROMAGNETIC RELAYS 2 Sheets-Sheet 2 Filed Aug. 30, 1963 FIG.6.

INVENTOR Walter J. Ric hert ATTORNEYS United States Patent 3,253,095ELECTROMAGNETIC RELAYS Walter J. Richert, Princeton, Ind., assignor toAmerican g Iachine & Foundry Company, a corporation of New ersey FiledAug. 30, 1963, Ser. No. 305,720 6 Claims. (Cl. 200-87) This inventionrelates to electromagnetic relays and, more particularly, to relays ofthe type in which the armature is retained in an actuated position bypermanent magnet means.

Relays of this particular type have become known in the trade asmagnetic latching relays. In the general type of relay to which thisinvention applies, a pivoted magnetic armature is actuated by anelectromagnet motor, selectively to two actuated positions, andpermanent magnet means is provided to retain the armature in at leastone of the actuated positions whenever that position is attained. Suchrelays may comprise two actuating electromagnets and a single permanentmagnet, as disclosed in US. Patent 2,955,174, issued October 4, 1960, toWalter J. Richert, or may be made with only a single electromagnet, asdisclosed in US. Patents 2,941,130, issued June 14, 1960, to JosefFischer et al., and 2,960,583, issued November 15, 1960, to Richard T.Fisher et al.

For many applications for such relays, particularly when the finishedrelay must be very small, it is highly desirable to employ only a singleelectromagnet, i.e., a single core equipped with one or more coils.However, because of the physical disposition of the singleelectromagnet, and the arrangements which are then possible for thearmature, the permanent magnet or magnets, and the contacts, it has beendifficult to construct a single electromagnet, permanent magneticlatching relay in such fashion that severe problems do not arise in bothmanufacture and operation of the relay. Normally, as in this invention,the armature is made to extend generally parallel to the axis of thecore of the electromagnet. However, with the known constructions ofrelays of this type, it is difiicult to find adequate space for thevarious elements of the relay without exceeding the space requirementsfor the relay.

In the single electromagnet latching relays used in the past, it hasbeen possible to maintain the length and width of the relay withincertain predetermined space requirements. However, in the relays ofFisher et al., 2,960,583, and Fischer et al., 2,941,130, the height ofthe relay as measured in a direction perpendicular to the base isseveral times the width of the relay. The difficulty with theseconstructions is that the contacts, armature, permanent magnet, and coilare mounted, respectively, in superposed relation relative to the base.

In the type of latching relay that employs two electromagnets such asthat of Richert 2,955,174, the height requirements could not bemaintained because the cores of the electromagnets were disposed withtheir axes perpendicular to the base.

In the relay of this invention, the problem of minute space requirementshas been solved by a unique arrangement of the various elements of thiselectromagnetic, permanent magnet latching relay that measures only A"in length, /8 in width and in height.

Another problem which was solved was that of establishing flux paths ofoptimum effectiveness for both the permanent magnet means and theelectromagnet. By the unique arrangement of elements of the magnetcircuit of this relay, the flux path for the electromagnet issubstantially improved as is the efficiency of the permanent magnetmeans in establishing a circuit for magnetically latching the relay whenthe electromagnet is unenergized.

A general object of the invention is to devise a relay ice of the typedescribed, involving only a single electromagnet as the actuating motor,which is free from the manufacturing and operational problems heretoforeencountered with such relays.

Another object is to provide such a relay that is extremely small and isso constructed that the electromagnet, permanent magnet means, andarmature are disposed in a plane parallel with and spaced from the planeof the base.

A further object is to provide a permanent magnet latching type relay,in which the permanent magnet'means is disposed outside the normal fluxpath of the relay.

A further object of this invention is to devise such a relay with abalanced armature that is extremely resistant to accidental switching athigh levels of shock and impact.

Yet another object is to device a magnetically latched relay in whichthe flux path for the electromagnet is substantially independent of theflux path for the permanent magnet to improve the operatingcharacteristics of the relay.

In order that the manner in which these and other objects are attainedin accordance with the invention can be understood in detail, referenceis had to the accompanying drawings, which form a part of thisspecification, and wherein:

FIG. 1 is a side elevational view of a relay constructed in accordancewith one particularly advantageous embodiment of the invention;

FIG. 2 is a top plan view of the relay of FIG.1;

FIG. 3 is an end elevational view of the relay of FIG. 1;

FIG. 4 is a side elevational view looking toward the side of the relaywhere the coil is located;

FIG. 5 is a plan view of the contacts and base with portions of therelay removed for clarity;

FIG. 6 is a view in exploded perspective of the several components ofthe relay; and

FIG. 7 is a schematic drawing showing the magnetic circuits of therelay.

Referring now to the drawings in detail, the embodiment of the inventionthere illustrated comprises a base 1, a contact and terminal assembly 2carried by the base, a motor structure 3 including a pivoted armature 4,and a bracket 5 that supports the motor structure. Although the relay isshown with the base horizontal and the motor structure above the base,it is to be understood that the relay is operative in any position withequal effectiveness.

Considering FIGS. 5 and 6, base 1 is seen to be a metal header in theform of a plate which has a flat major surface 6 that faces motorstructure 3 and a flat major surface 7 on the side of the base oppositefrom the motor structure. Base 1 is rectangular, and has straight edgesat sides 8 and 9 of approximately twice the length of straight edges atends 10 and 11. At side 8- are two spaced apart recesses 12 and 13 whichhave a bottom wall 14 parallel to major surface 6 and a rear wall 15parallel to the surface of side 8. Recesses 16 and 17, identical torecesses 12 and 13, are also provided at side 9 of the base. rear wall15 of each recess, as by welding, so that a portion of the tongueprojects beyond major surface 6 generally at right angles thereto. Therecesses and tongues 18 provide mounting supports for securing bracket 5to the base, as will subsequently be described.

Terminal and contact assembly 2 includes a plurality of terminal pins19-28 that extend through a plurality of openings 29 in base 1. The pinsare secured in place by being embedded in masses of suitable insulatingmaterial filling the openings 29, in the usual manner.

The arrangement of terminal pins on base 1 is such that pins 19-22 aredisposed at the corners of an imaginary square formed by linesconnecting the axes of ad- A flat tongue 18 is secured tojacent ones ofthe pins. Terminal pin 23 is disposed at the intersection of thediagonals of the imaginary square thus formed. At the other side of thebase, the axes of pins 24-27 are similarly disposed at the corners of animaginary square, with pin 28 at the intersection of the diagonals ofthat square. In addition, the pins at each side of the relay have theiraxes on the same straight line and are equidistantly spaced.

The terminal pins project a sufficient distance beyond major surface 7of base 1 to permit plugging the terininals into a suitable socket (notshown), the ends of the pins being rounded to facilitate inserting sameinto the socket. The portions of the pins opposite the rounded endsproject above major surface 6 of the base to provide supports for thefixed and movable contacts, and connecting pins for the electrical leadsfrom the motor structure 3.

As best seen in FIG. 5, pins 19 and 20 support fixed bent leaf contacts30 and 31 adjacent end 11 of the base, and pins 26 and 27 support fixedbent leaf con tacts 32 and 33 adjacent end of the base, each of thefixed contacts having bifurcated contact ends. Extending between fixedcontacts 30 and 31 is a movable leaf-type contact 34 supported by pin25. Fixed contacts 30 and31 coact with movable contact 34 to form asingle pole, double throw switch. The space between fixed leaf-typecontacts 30 and 31, where movable contact 34 projects between thesecontacts, is offset in a direction toward side 8 of the base, so thatmovable contact 34 can be moved from contact 30 to contact 31 withoutengaging the centrally located terminal pin 23.

The arrangement of fixed and movable contacts at end 10 of the base isthe same as for the contacts adjacent end 11, and the space betweenfixed contacts 32 and 33 is also offset toward side 8 of the base, sothat a movable leaf-type contact 35 secured to pin 22 can be moved fromfixed contact 32 to fixed contact 33 without engaging the terminal pin28.

Fixed contacts 31 and 32 are substantially identical, having free endsthat terminate short of the free ends of movable contacts 34, 35 toleave exposed surfaces on the sides of the movable contacts that facetoward side 8 of the base. These exposed surfaces are provided forengagement with suitable pushers to armature 4 to operate the contacts.

As best seen in FIG. 6, contacts 30-35 are leaf spring type contacts ofsubstantially similar width disposed in a plane spaced slightly abovemajor surface 6 of base 1.

Motor structure 3 is fixed to bracket 5, which in turn is secured tobase 1. Motor structure 3 includes an elongated electromagnet 36comprising a cylindrical core 37 surrounded by two coils .38 and 39. Thecoils are wound on suitable insulating bobbins in end-to-end relationwith the ends 40 of the core projecting beyond the ends of the bobbin.Ends 40 are turned to a smaller diameter than the body portion of thecore to provide a cylindrical tip that projects axially at each end ofthe core from a transverse annular shoulder 41. There is secured to eachexposed end 40 a flat magnetic member 42, the members 42 extendingtransversely of the core and parallel to each other. Members 42 areidentical, each including a circular portion 43 of a diameterapproximately equal to the diameter of coils 38 and 39. Each circularportion 43 has a centrally located bore 44 through which the ends 40project when the members 42 are placed on the core and moved axiallytoward the coils into engagement with annular shoulders 37. The members42 are then secured to the core by mechanically deforming the exposedtips of ends 40. Each member 42 also includes an integral rectangularportion 45 which extends away from the core to terminate in a straightend edge 46. Rectangular portions 45 are aligned with each other axiallyof the electromagnet, so that end edges 46 lie in a common plane.

A pair of identical permanent magnets 47, 48 which are rectangular inside elevation and transverse cross section are disposed between thefree ends of rectangular portions 45, the magnets each having an endengaged with an fixed to the end portion of a different one ofrectangular portions 45. Magnets 47, 48 lie in a common plane parallelto the axis of core 37 of the electromagnet and are of such length thattheir adjacent ends are spaced apart. A rectangular member 49 of amagnetic material fills the space between the adjacent ends of themagnets, the rectangular member being fixed to the adjacent ends of themagnets. The rectangular member has substantially the same height as themagnets but is slightly thicker so that a face 50 projects beyond theadjacent surfaces of the magnets in a direction toward theelectromagnet, the surfaces on the sides opposite from the electromagnetbeing in a common plane to form a smooth surface along that side.

Magnetic members 42 are of such length, as compared to the diameter ofthe coils and the thickness of the magnets, that there is a substantialspace between the magnets and the coils to accommodate pole pieces 51and 52, and the armature. The pole pieces are each L-shaped and ofrectangular cross-sectional configuration. The pole pieces are disposedwith a short leg 53 parallel with and fixed to rectangular portion 45 sothat a leg 54 extends parallel to the axis of the coils and adjacent theside thereof to provide exposed pole faces 55 and 56 projectingperpendicularly from opposite ends of the electromagnet. Pole faces 55and 56 are spaced from the permanent magnets a distance sufficient toaccommodate the armature. Ends 57 of short legs 53 have spaced aparttips on each side of a concave portion 58 (FIG. 3), the tips onlyabutting the permanent magnets adjacent the ends of the magnets with theconcave portion spaced from the magnet. The concave portion 58 iseffective to prevent ends 57 of legs 53 from shunting a portion of thepermanent magnet. Such shunting, which is effective to decrease theeffective length of the permanent magnet, and hence the strength of theflux produced by the magnet, is essentially avoided by thisconstruction. Thus, core 37 of the electromagnet, and magnetic members42, cooperate to define a rigid magnetic structure which can beconsidered to be generally in the form of a shallow U, with magneticmembers 42 defining the legs of the U and the pole pieces 51 and 52presenting exposed pole faces 55 and 56 parallel to the base of the U infacing relationship with the permanent magnets. The permanent magnets 47and 48 and rectangular member 49 combine to form a magnetic structure 59that extends between the legs of the U and is parallel to the base ofthe U. With magnetic structure 59 in position between the ends ofmembers 42, it is apparent that a rectangular flux path is provided, themembers comprising the rectangular flux path being in a plane parallelwith the base. Therefore, it is apparent that the pole faces 55 and 56are located between permanent magnets 47 and 48 and coils 38 and 39 withthe legs 54 that define the pole faces being immediately adjacent to thesides-of the coils.

Bracket 5 is formed from sheet metal that is preferably nonmagnetic. Thebracket includes a rectangular frame having sides 60 and 61 and ends 62and 63, each of the ends being curved a short distance from side 60 toconform to the configuration of magnetic member 42 so that therectangular magnetic structure defined by the core, magnetic structure59, and magnetic members 42 is disposed in a plane parallelwith andspaced above base 1. A pair of legs 64 project toward the base from side60 and another pair of legs 65 project toward the base from side 61 atthe opposite side of the bracket. The legs are generally triangular andterminate in rectangular tips 66 which are so spaced that they alignwith and are disposed in recesses 12, 13 and 16, 17 in such a mannerthat the inwardly facing surfaces of the legs engage tongues 18, thesesurfaces being secured to the tongues 5. by welding. Due to thecurvature of ends 62 and 63, side 60 of the bracket is disposed in aplane between the base and the plane of side 61, and hence it isapparent that legs 64 are slightly shorter than legs 65. Adjacent thesides of rectangular tips 66 are edges 66 of legs 64, the edges abuttingmajor surface 6 of the base to properly space the motor structure fromthe base. Extending toward side 60 from the center side 61, in a planeparallel with base 1, is an car 67 that is domed in a direction towardthe motor structure 3, the domed portion having a central opening 68which provides a bearing for one side of the armature.

As best seen in FIG. 6, armature 4 is in the form of an elongatedrectangle when viewed in side elevation and has a rectangular transversecross section. Integral pivot pins 69 project at right angles from thecenters of opposite ones of the long edges of the armature. As best seenin FIG. 2, the armature is disposed between electromagnet 36 andpermanent magnets 47 and 48 and is of such length that a portion of therectangular face of the armature extends across each of the pole faces55 and 56. Pivot pin 69 which projects toward the base extends intoopening 68 of ear 67, whereas pivot pin 69 which projects away from thebase extends through an opening 70 in a bracket member 71 that issecured to the fixed magnetic structure 59 along the edge opposite theedge that is secured to bracket 5. Bracket 71 is preferably ofnonmagnetic material and has an ear 72 projecting in the same directionas and parallel with ear 67. Bar 72 is domed downwardly concentric withopening 70 so that the space between the domed portions of ear 67 andcar 72 is exactly the same as the distance between the long edges of thearmature from which the pivot pins extend.

At each side of the pivot, the rectangular face of the armature isprovided with a domed portion 73 and 74 that projects toward thepolefaces 55, 56 and engages a pole face when the relay is in operation.The ends of the armature are angled slightly in a direction away fromthe pole faces so that only the domed portions engage a pole face.

. Fixed adjacent each end of that long edge of the armature which facesthe base is a contact operating pusher in the form of a curved stiffwire, the contact operating pushers 75 and 76 projecting toward base 1through the opening in the frame of bracket and having at their freeends pusher beads 77 and 78 of insulating material that engagerespectively with the exposed portions of the free ends of movablecontacts 34 and 35.

Due to the latching effect of the permanent magnet, the armature isalways disposed in either a first position in which it contacts and ismagnetically latched to pole face 55, or a second position in which itcontacts and is magnetically latched to pole face 56. It is to be notedthat face 50 of rectangular member 49 has a first side edge which isclosely adjacent a rear surface of the armature at one side of the pivotwhen the armature is in its first position, and has a second side edgeopposite the first which is closely adjacent a rear surface of thearmature on the other side of the pivot when the armature is in itssecond position. Hence, in either position of the armature, a veryminute air gap is-forme'd between the armature and an edge ofrectangular member 49. However, the gap is much greater during thepivotal swing of the armature which is an important feature the purposeof which will subsequently be described.

Thus, in the relay of this invention, motor structure 3 is supported bybracket 5. The axis of core 37, as best seen in FIGS. 2 and 3, isdisposed parallel with side 9 of the base and is offset from the centerof the relay toward the side 9. Armature 4 is offset toward side 8 ofthe base from the center thereof, the pivotal axis of the armature,defined by pins 69 and hearings in brackets 5 and 71, beingperpendicular to base 1 at a point offset toward side 8 of the base fromthe center of the base. By virtue of this arrangement, the height of therelay in a the base to hermetically seal the relay.

Turning now to the schematic drawing of FIG. 7 which shows the variouselectrical and magnetic circuits of the relay, the operation of therelay will be described.

Although there are several coil and operating arrangements that can beused to operate latching relays of this type, only the operation of thepreferred embodiment which employs two coils to respectively latch andreset the armature will be described. To simplify the description ofoperation of the relay, the effect of the permanent magnet flux on theflux of the electromagnet will not be considered, since the effect isnot significant.

In the position shown in FIG. 7, armature 4 engages pole face 56 and ismagnetically latched in this position because of the effect ofpermanentmagnet 47. The flux from permanent magnet 47 follows the path shown indot-dash lines and flows from the north pole of magnet 47, through aportion of member 42, then through pole piece 52, across pole face 56into armature 4, then across the air gap between the armature andrectangular member 49, and back to magnet 47 to complete the flux path.Since magnet 48 is disposed with its south pole adjacent the south poleof magnet 47, a similar flux path will be formed when the armature ispivoted to engage pole face 55. 5

To pivot the armature from the position of FIG. 7 to the position inwhich the armature engages pole-face 55, it is necessary that themagnetic attractive force between pole face 55 and the armature exceedthe latching force of magnet 47. However, it is also necessary that theelectromagnetic flux be of the proper polarity to assist the flux due tomagnet 48. The flux due to magnet 48 follows a path similar to that ofmagnet 47, but in the opposite direction, the flux from magnet 48flowing in a clockwise direction through end member 42, pole face 55,the air gap between pole face 55 and the armature (when the armature isin the FIG. 7 position), the armature itself, rectangular member 49, andback to magnet 48. Energizing coil 38 to create a flux that travelscounterclockwise, as shown in FIG. 7 in solid lines, is effective topivot the armature to a position in which it engages pole face 55. Theflux of the electromagnet travels primarily through the pole pieces,armature, and core, and when coil 38 is energized the counterclockwiseflux assists the flux of magnet 38 to increase the magnetic attractionbetween pole face 55 and the armature. As soon as the electromagneticflux begins to move the armature toward pole face 55, the magneticcircuit due to magnet 47 opens and the armature switches instantaneouslyinto engagement with pole face 55. As the armature begins to move, theair gap between rectangular member 49 and the armature increases, theincrease in that air gap further reducing the effect of magnet 47 tomaintain the armature in the FIG. 7 position, so that the armaturequickly switches. To return the armature to the FIG. 7 position, coil 39is energized as shown to create flux in a clockwise direction, (notshown) whereupon the flux assists magnet 47 and the armature againengages pole face 56.

Beads 77 and 78, carried at opposite ends of the armature, actuatecontacts 34 and 35, respectively. When the armature is in one positionwith domed portion 73 engaging pole face 55, head 78 holds contact 35 inengagement with fixed contact 33, and movable contact 34 engages fixedcontact 31 because of the spring properties of contact 34, bead 77 beingspaced slightly from the movable contact (FIG. 5). When the armature isswitched so that domed portion 74 engages pole face 56, bead 77 movesmovable contact 34- into engagement with fixed contact 30, andsimultaneously bead 78 moves away from movable contact 35 to allow themovable contact to return by its own resiliency into engagement withfixed contact 32. Hence, the movable contacts exert a force against thearmature in a direction to oppose the latching magnet. This opposingforce assists switching of the armature from one position to the otherwhen the electromagnet is properly energized. Even though the contacts30 and 33 are termed fixed contacts, these con tacts have naturalresiliency, being formed of spring material having good electricalconducting properties, and being supported at one end only. Hence, thesecontacts are flexed somewhat when the movable contacts are brought intoengagement with them. The resiliency of contacts 30 and 33 also tends tomove the armature to oppose the latching magnet. These opposing forcesof both the fixed and movable contacts combine to assist switching ofthe armature by the electromagnet.

Although a preferred embodiment of the relay of this invention has beendescribed and shown in detail, it is to be understood that the scope ofthe invention is not limited thereto and that numerous changes andramifications can be made without departing from the scope of theinvention.

What is claimed is: 1. In a compact miniature electromagnetic relay, thecombination of a header comprising a flat rectangular support member anda plurality of conductive pins extending therethrough; a motorstructure; means mounting said motor structure on said support member inspaced relation thereto; and a contact assembly including fixed andmovable contacts carried by said pins and disposed between said motorstructure and said support member, said motor structure comprising anelectromagnet having an elongated magnetic material core extendingparallel to said support member and a coil surrounding said core, saidcore being parallel to two of the sides of said support member andoffset from the center of said support member toward one of said sides,

a pair of straight flat magnetic end members coupled to the ends of saidcore and projecting laterally therefrom in aligned relation relative tosaid core, r

a substantially straight continuous elongated magnetic structureextending between said end members in spaced parallel relation to saidelectromagnet,

said core, said end members and said magnetic structure cooperating todefine a generally rectangular flux path parallel to said supportmember, and

an elongated magnetic material armature disposed for pivotal movementabout an axis perpendicular to said support member, said armature beingdisposed between said magnetic structune and said electromagnet withinthe bounds of said rectangular flux path, and

magnetic material pole pieces between said armature and said coil, saidpole pieces being magnetically coupled to said end members and eachproviding a pole face directed away from the axis of said core;

said substantially straight elongated magnetic structure comprising afirst straight permanent magnet having an end secured to one of said endmembers,

a second straight permanent magnet having an end secured to the other ofsaid end members,

said permanent magnets extending toward each other and terminating atfacing ends spaced from each other, and magnetic material meansconnecting the facing ends of said permanent magnets; one of saidpermanent magnets being effective to magnetically latch said armature toone of said pole faces when said armature is in a first positionengaging said one of said pole faces and the other of said magnets beingeffective to latch said armature to the other of said pole faces whensaid armature is in a second position engaging the said other of saidpole faces. 2. An electromagnetic relay in accordance with claim 1 inwhich said pole pieces are L-shaped, a first leg of each of said polepieces defining said pole faces, and a second leg of said pole piecesbeing in abutting relation with said respective end members, the ends ofsaid second legs of said pole pieces abutting said magnetic structure.3. An electromagnetic relay in accordance with claim 2 in which saidends of said second legs of said pole pieces abut the respectivepermanent magnets of said magnetic structure, and said ends of saidsecond legs of said pole pieces are recessed to engage the permanentmagnets at areas less than the cross sectional area of a leg, whereby adecrease in the effective length of said permanent magnets as a resultof the magnetic shunting effect of said second legs of said pole piecesis avoided. 4. In a compact, miniature, magnetically latchingelectromagnetic relay, the combination of a flat rectangular header amotor structure; means mounting said motor structure on said header inspaced relation thereto 7 a contact assembly comprised of stationary andmovable contacts carried by said header and disposed between said motorstructure and said header said motor structure comprising anelectromagnet having an elongated core extending parallel to saidsupport member and a coil surrounding said core, said core beingparallel to two of the sides of said support member and offset from thecenter of said support member toward one of said sides, first and secondmagnetic members fixed to the opposite ends respectively of said core,said members extending transversely from said core and terminating atends aligned with each other, a continuous magnetic structure fixed toand extending between the ends of said first and second magneticmembers, first and second pole pieces magnetically coupled to theopposite ends of said core and extending toward each other parallel withand closely ad- .jacent said electromagnet, to present a pair of polefaces facing away from said electromagnet, an armature disposed betweensaid magnetic structure and said pole pieces, and contact operatingmeans carried by said armature; said magnetic structure including firstand second permanent magnets said means mounting said motor structure onsaid header being in the form of a first non-magnetic bracket comprisinga motor structure supporting portion fixed to at least said magneticstructure of said motor structure, and a plurality of legs on saidsupporting portion and fixed to said header;

a second non-magnetic bracket in engagement with and secured to saidcontinuous magnetic structure means on said first and second brackets tomount said armature for pivotal movement to a first position in whichone end of said armature engages one of said pole faces, and a secondposition in which the other end of said armature engages the other ofsaid pole faces; said electromagnet providing means to move saidarmatune to said first and second positions; and said permanent magnetsbeing effective to magnetically latch said armature in either of saidpositions. 5. An electromagnetic relay in accordance with claim 4 inwhich said motor supporting portion of said first bracket is in the formof a rectangular frame with an opening therein completely bounded by theframe, and said means carried by said armature to operate said contactsextends through said opening of said frame.

10 6. An electromagnetic relay in accordance with claim 4 in which theends of said armature are each provided with domed projections whichengage said pole faces.

References Cited by the Examiner UNITED STATES PATENTS 2,203,888 6/1940Ashworth 317-172 2,846,542 8/1958 Stanley 200 93 3,109,903 11/1963Lychyk 20087 3,138,677 6/1964 Adams 317 197 X FOREIGN PATENTS 108,4128/1939 Australia.

BERNARD A. GILHEANY, Primary Examiner. JOSEPH J. BAKER, AssistantExaminer.

1. IN A COMPACT MINIATURE ELECTROMAGNETIC RELAY, THE COMBINATION OF AHEADER COMPRISING A FLAT RECTANGULAR SUPPORT MEMBER AND A PLURALITY OFCONDUCTIVE PINS EXTENDING THERETHROUGH; A MOTOR STRUCTURE; MEANSMOUNTING SAID MOTOR STRUCTURE ON SAID SUPPORT MEMBER IN SPACED RELATIONTHERETO; AND A CONTACT ASSEMBLY INCLUDING FIXED AND MOVABLE CONTACTSCARRIED BY SAID PINS AND DISPOSED BETWEEN SAID MOTOR STRUCTURE AND SAIDSUPPORT MEMBER, SAID MOTOR STRUCTURE COMPRISING AN ELECTROMAGNET HAVINGAN ELONGATED MAGNETIC MATERIAL CORE EXTENDING PARALLEL TO SAID SUPPORTMEMBER AND A COIL SURROUNDING SAID CORE, SAID CORE BEING PARALLEL TO TWOOF THE SIDES OF SAID SUPPORT MEMBER AND OFFSET FROM THE CENTER OF SAIDSUPPORT MEMBER TOWARD ONE OF SAID SIDES, A PAIR OF STRAIGHT FLATMAGNETIC END MEMBERS COUPLED TO THE ENDS OF SAID CORE AND PROJECTINGLATERALLY THEREFROM IN ALIGNED RELATION RELATIVE TO SAID CORE, ASUBSTANTIALLY STRAIGHT CONTINUOUS ELONGATED MAGNETIC STRUCTURE EXTENDINGBETWEEN SAID END MEMBERS IN SPACED RELATION TO SAID ELECTROMAGNET, SAIDCORE, SAID END MEMBERS AND SAID MAGNETIC STRUCTURE COOPERATING TO DEFINEA GENERALLY RECTANGULAR FLUX PATH PARALLEL TO SAID SUPPORT MEMBER, ANDAN ELONGATED MAGNETIC MATERIAL ARMATURE DISPOSED FOR PIVOTAL MOVEMENTABOUT AN AXIS PERPENDICULAR TO SAID SUPPORT MEMBER, SAID ARMATURE BEINGDISPOSED BETWEEN SAID MAGNETIC STRUCTURE AND SAID ELECTROMAGNET WITHINTHE BOUNDS OF SAID RECTANGULAR FLUX PATH, AND MAGNETIC MATERIAL POLEPIECES BETWEEN SAID ARMATURE AND SAID COIL, SAID POLE PIECES BEINGMAGNETICALLY COUPLED TO SAID END MEMBERS AND EACH PROVIDING A POLE FACEDIRECTED AWAY FROM THE AXIS OF SAID CORE; SAID SUBSTANTIALLY STRAIGHTELONGATED MAGNETIC STRUCTURE COMPRISING A FIRST STRAIGHT PERMANENTMAGNET HAVING AN END SECURED TO ONE OF SAID END MEMBERS, A SECONDSTRAIGHT PERMANENT MAGNET HAVING AN END SECURED TO THE OTHER OF SAID ENDMEMBERS, SAID PERMANENT MAGNETS EXTENDING TOWARD EACH OTHER ANDTERMINATING AT FACING ENDS SPACED FROM EACH OTHER, AND MAGNETIC MATERIALMEANS CONNECTING THE FACING ENDS OF SAID PERMANENT MAGNETS; ONE OF SAIDPERMANENT MAGNETS BEING EFFECTIVE TO MAGNETICALLY LATCH SAID ARMATURE TOONE OF SAID POLE FACES WHEN SAID ARMATURE IS IN A FIRST POSITIONENGAGING SAID ONE OF SAID POLE FACES AND THE OTHER OF SAID MAGNETS BEINGEFFECTIVE TO LATCH SAID ARMATURE TO THE OTHER OF SAID POLE FACES WHENSAID ARMATURE IS IN A SECOND POSITION ENGAGING THE SAID OTHER OF SAIDPOLE FACES.